Which is best for blog SEO: separate domain, subdomain or subfolder?

Where you host your blog relative to your main site is one of the more important decisions involved with setting up a blog.

If you get the decision wrong, you may fail to get the hoped for SEO benefits you have worked hard to convince your colleagues about. But, if you get it right you can almost immediately see new, incremental visits you wouldn't have attracted without the blog.

So which is the best blog hosting option for SEO?

I often ask this question in my SEO classes and ask for a show of hands to see what folk think. It's a bit of a trick question since there is no right or wrong answer - it depends whether you or your colleagues take a short or long-term perspective. That said, most people say Subfolder is best and this is what various Tweets and Facebook comments on a recent question on subfolder or subdomain in the Smart Insights Linked In Best Practices group showed.

But you can argue each case, particularly if you look beyond SEO at branding benefits you may get from a separate domain. Here are the pros and cons as I see them. What do you think?

1. Subfolder

+ Google will crawl new blog posts typically within days of launch

+ Blog inherits the authority of parent site so can rank immediately for terms within posts

+ Backlinks and social mentions generated by the content on the blog can help other contain on the domain i.e. product pages rank more highly

+ Integrates better with main site for better user experience (although often will have a different design)

+ Easier to track with Google Analytics - a minor point - see end of post

- Doesn't help generate external backlinks for which you control the anchor text, e.g. editorial links within blog copy

2. Subdomain

+ Maybe technically easier for some setups

+ Has some of the benefits of subfolder in inheriting parent domain authority and separate domain in providing backlinks to main site, but...

- Needs to establish its own reputation through backlinks from other sites so...

- Will not rank as highly or as quickly as a subfolder

3. Separate domain

+ Helps you control and generate external backlinks for which you control the anchor text, i.e. editorial links within blog copy back to category and product pages

+ Can create a more differentiated brand identity which can be seen as independent from the main site so generates more engagement with it's audience potentially

+ Can target a different country, i.e. I have seen UK companies launching a US hosted blog

- You may not rank competitively at all for weeks or months depending on the quality of the content you create. This may be hard to sell to your colleagues investing in it - it's an act of faith...

- Will require a long-term commitment to content creation and backlink development

So, to summarise 1 is the safe option, but if you create exceptional content which creates a lot of backlinks then 3 can be valuable in providing links back to the main site from a separate authority site you control. What do you think?

An "experiment" to test subfolder vs subdomain

In 2008, before we launched Smart Insights I setup a new WordPress blog to replace my legacy blog, which backs up what I'm saying.

Initially I set it up on a subdomain http://blog.davechaffey.com.

I pointed all my run-of-site nav links at this sub-domain.

I think I felt that the longer-term benefits of being on a sub-domain and pointing back to the main site might give some SEO benefits.

After a week it was in the index, but not featuring for any 3-4 keyword searches, so I lost patience and 301 redirected the sub-domain to http://www.davechaffey.com/blog and changed all the run-of-site links and links from other sites to this new address.

Within 4 or 5 days i was starting to appear for long tail 5 or 6 keyword searches and within a fortnight appearing on first page for blog titles/shorter searches.

So based on that, I'd recommend subfolders is the way forward for blogs if you want to swiftly pull in visitors based on the authority of your existing domain.

That'll be obvous to many, but I wanted to trial it and that's what I've found.

Subdomains and subfolders for Google Analytics

When I taking my Google IQ qualification recently I thought of another minor benefit of the subfolder approach.

Since Google Analytics serves first-party cookies for each different domain or sub-domain, this will mean that sub-domains aren't tracked as part of an integrated whole site. But they are integrated if they are part of a subfolder.

With a subfolder as the one on this site, it's recommended that a profile is setup with an include filter for a subdirectory ^/blog/ so you can still isolate traffic for that part of site.

By Dave Chaffey

Digital strategist Dr Dave Chaffey is co-founder and Content Director of Smart Insights. Dave is editor of the 100+ templates, ebooks and courses in the digital marketing resource library created by our team of 25+ Digital Marketing experts. Our resources are used by our Premium members in more than 100 countries to Plan, Manage and Optimize their digital marketing. Free members can access our sample templates here.
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Dave is a keynote speaker, trainer and consultant who is author of 5 bestselling books on digital marketing including Digital Marketing Excellence and Digital Marketing: Strategy, Implementation and Practice. In 2004 he was recognised by the Chartered Institute of Marketing as one of 50 marketing ‘gurus’ worldwide who have helped shape the future of marketing.